Citation and License

Arthritis Res Ther 2004, 6:R264-R272
doi:10.1186/ar1173

Published: 26 April 2004

Abstract

The aim of the present study was to investigate the effect of long-term infliximab
treatment on various autoantibodies in patients with rheumatoid arthritis. Serum samples
from 30 consecutive patients, who were prospectively followed during infliximab and
methotrexate therapy for refractory rheumatoid arthritis, were tested at baseline
and after 30, 54 and 78 weeks. At these points, median values of the Disease Activity
Score were 6.38 (interquartile range 5.30–6.75), 3.69 (2.67–4.62), 2.9 (2.39–4.65)
and 3.71 (2.62–5.06), respectively. Various autoantibodies were assessed by standard
indirect immunofluorescence and/or ELISA. Initially, 50% of patients were positive
for antinuclear antibodies, and this figure increased to 80% after 78 weeks (P = 0.029). A less marked, similar increase was found for IgG and IgM anticardiolipin
antibody titre, whereas the frequency of anti-double-stranded DNA antibodies (by ELISA)
exhibited a transient rise (up to 16.7%) at 54 weeks and dropped to 0% at 78 weeks.
Antibodies to proteinase-3 and myeloperoxidase were not detected. The proportion of
patients who were positive for rheumatoid factor (RF) was similar at baseline and
at 78 weeks (87% and 80%, respectively). However, the median RF titre exhibited a
progressive reduction from 128 IU/ml (interquartile range 47–290 IU/ml) to 53 IU/ml
(18–106 IU/ml). Anti-cyclic citrullinated peptide (CCP) antibodies were found in 83%
of patients before therapy; anti-CCP antibody titre significantly decreased at 30
weeks but returned to baseline thereafter. In conclusion, the presence of anti-double-stranded
DNA antibodies is a transient phenomenon, despite a stable increase in antinuclear
and anticardiolipin antibodies. Also, the evolution of RF titres and that of anti-CCP
antibody titres differed during long-term infliximab therapy.